Hydrometallurgical treatment of metal-bearing materials, such as metal ores, metal-bearing concentrates, and other metal-bearing substances, has been well established for many years. Moreover, leaching of metal-bearing materials is a fundamental process utilized to extract metals from metal-bearing materials. In general, the first step in this process is contacting the metal-bearing material with an aqueous solution containing a leaching agent which extracts the metal or metals from the metal-bearing material into solution. For example, in copper leaching operations, especially copper from copper minerals, such as chalcopyrite and chalcocite, sulfuric acid in an aqueous solution is contacted with copper-bearing ore. During the leaching process, acid in the leach solution may be consumed and various soluble components are dissolved thereby increasing the metal content of the aqueous solution. Other ions, such as iron may participate in the leaching of various minerals as these ions participate in dissolution reactions.
Additionally, under these current leaching processes, especially copper from copper sulfides such as chalcopyrite and chalcocite, large concentrations of dissolved silica are generated. This dissolved silica is gradually transformed to colloidal silica. Large amounts of this colloidal silica can agglomerate within process equipment, which may lead to inefficiencies in subsequent solvent extraction steps and low overall process yields. Additionally, this colloidal silica residue can result in impurities in the extracted metal (i.e. impurities in metal deposited during electrowinning steps).
Accordingly, a process that enables efficient metal recovery and provides relief from supersaturation of dissolved silica in pregnant leach solutions, thereby reducing silica within the metal recovery process, would be advantageous.